1. Field of the Invention
This invention relates to the field of computer monitor emulation by television receivers, and in particular, by wide screen television receivers.
2. Description of Related Art
Current wide screen televisions, for example as described in published specification PCT/US91/03740, corresponding to U.S. Pat. No. 5,442,406, do not have the capability of displaying analog computer RGB signals. There is a need for a modification to current television receivers, particularly wide screen television receivers, that would enable a display of analog computer RGB inputs with separate horizontal and vertical synchronization signals.
Current wide screen television receivers, as described, can accept analog RGB inputs through a 2f.sub.H (double horizontal rate scanning, for example, progressive horizontal scanning) input/output module or circuit inside the television. Such a module or circuit provides a method of interfacing external 2f.sub.H inputs (either RGB or YPrPb) into the internal video signal processing signal path, downstream from the point where conventional 1f.sub.H input video signals are converted for progressive 2f.sub.H scanning. The synchronization signals come from either the composite sync input or y (of RGB inputs) or from the composite sync on luma (for the YPrPb inputs).
VGA computer monitors operate at a horizontal frequency of 31.47 KHz, that is, at 2f.sub.H. Current wide screen television receivers already have the capability of receiving and displaying analog RGB inputs at a horizontal frequency of 31.47 KHz. The problem is that a typical 2f.sub.H input/output module requires composite sync for the RGB inputs rather than the separate horizontal and vertical synchronizing signals from the VGA computer inputs.